Noisy Waveform Restoration using DFT in MATLAB

Code:

clc

clear all

close all

t=0:0.01:2*pi;

x=sin(t)+sin(2*t);

subplot(2,2,1);

plot(t,x);

title('Original signal');

xlabel('Time');

ylabel('Amplitude');

n=rand(1,length(t));

x=x+n;

subplot(2,2,2);

plot(t,x);

title('Noise corrupted signal');

xlabel('Time');

ylabel('Amplitude');

g=fft(x);

subplot(2,2,3);

plot(abs(g));

title('Magnitude part of fft');

f=find(abs(g)<50);

g(f)=zeros(size(f));

w=ifft(g);

subplot(2,2,4);

plot(w);

title('Signal after noise removal');

xlabel('Time');

ylabel('Amplitude');